* No need to have a second device present to stream music. That is, I can start up music with the controller on my phone, and go to the store, but the music still plays since all the streaming is handled by the sonos speaker.
* No need to pair your phone/computer to the device every time you come home. Just get on the wifi, and you're set.
Those are the big ones for me, and honestly they're huge.
On the flip side, the biggest pain point is that you're beholden to whatever music services they include in their controller, and you have to use their controller to play music. So while they support Apple Music, I can't use the Music app on my phone to play it. I have to drill through the Sonos app and find what I want. It works pretty well, but it's annoying. Also, I can't stream Audible books, or Overcast podcasts since they aren't supported by the Sonos controller.
Also, activating Bluetooth is as frictionless as activating WiFi.
Not in my experience. Bluetooth is functional, but it's hard to call it better.
* Connecting 2 people (phones) to one device is hardly supported.
* Those 2 people can't really manage a single playlist without special effort.
* Auto connecting to a bluetooth speaker when I walk in the house doesn't happen. It does with wifi.
* Connecting to the bluetooth speaker typically kicks off any other connection
* The issue of walking too far from the bluetooth speaker with the playing device still exists.
* Ever run the microwave while streaming audio over bluetooth? It doesn't work.
In my experience, bluetooth is better at one thing: streaming whatever audio from whatever app I want.
Sonos allows my wife and I to simply play whatever music we want, wherever we want, with no hassle. And it sounds great.
Oh my, no. Activating bluetooth is so frustrating that Apple built a special chip to make it easier. That Sonos work over Wifi and not Bluetooth is the primary selling point.
(Disclaimer: I used to work for Sonos.)
In particular, non-technical users appear to be vastly more comfortable with the Sonos system.